About this item 【Advanced Bluetooth 5.2 Technology】RUSAM BL31 built-in Bluetooth 5.2 chip,stable connection within 10 meters, Even if you cover your ears with your hands, you won't be disconnected,smooth like a wired headset. 【8 mm Large Dynamic Driver&Immersive Listening Experience】AAC/SBC dual audio decoding, 8mm DD unit with high-density composite diaphragm, strong bass effect.High and medium audio frequencies are clear and natural,Heavy and low frequency all around the ear. 【Feature rich】Digital electronic display/AAC Advanced Audio Coding/Pick Up to Use Quick Connecting/voice assistant/Dual hosts-Headphone master-slave automatic switching,Mainstream configuration has everything. 【Long battery life】Built-in 50MAH battery in the headset, 400MAH battery in the charging box, can listen to music continuously for 3-4 hours, and the charging box can be charged 4-5 times,and the play time or music time can be up to 14 hours with the charging compartment. 【Lightweight Ergonomically Design】The portable charging box and earphones are small and exquisite,comfortable to wear,the colors are beautiful and not dazzling, and the single earphone weighs only 4 grams.